James s



UNIT D STATES PATENT OFFICE.

JAMES S. HARKINS, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR OF ONE-HALF TO JACOB MERRITT, OF SAME PLACE.

BOILER-FURNACE.

SPECIFICATION forming part of Letters Patent No. 425,072, dated April 8, 1890.

Application filed January 2'7, 1890. Serial No. 338,214- (No model.)

To all whom it may concern: inside walls 25 and 27 are preferably corru- Be it known that I, JAMES S. HARKINS, of gated, as shown in Fig. 3. An inner lining Minneapolis, in the county of Hennepin and of fire-clay 30, corrugated to register with the State of Minnesota, have invented certain new corrugations on the walls 25 and 27, is so arand useful Improvements in Boiler-Furnaces, ranged as to form a number of openings or 55 of which the following is a specification. diving-flues 19 from the fire-box down on the The object of my invention is to provide outside of the lining 30, and the inner walls a furnace for generating heat which will by 25 and 27, leading to the main exit-flue 33, means of its construction and the co1nbinaformed by the rear wall 28 and the bottom tion of its several parts consume the fuel of the boiler 5 and the ground 34 beneath, 60

more perfectly, and at the same time obviate said flue being preferably lined with fire-brick the use of what is commonly termed a smoke- 35, or other suitable material. consumer, thereby utilizing to the fullest eX- In the front plate 10 are openings 37, leadtent the heating properties of the fuel. ing into the opening 38 in the walls of the I5 In the accompanying drawings, forming a fire-pot. The inner walls 25 on the side and 65 part of this specification, Figure 1 is a longithe walls 27 and 28 in the rear are provided tudinal vertical section of a boiler and furwith a series of holes 39 for the admission of nace embodying my improvements. Fig. 2 air through the openings in the walls into the is a front elevation and partial vertical secfire-pot and through into the smoke-flue 33.

20 tion of the same on liney y of Fig. 1. Fig. 3 is Leading from the steam-dome of the boiler 70 a horizontal section on line a: a; of Fig. 1. or other suitable steam-receptacle is a steam- In the drawings, 2 represents the outer or pipe 40, which is preferably placed in the holsupporting wall; 3, a cross-Wall forming the low Wall of the fire-pot, from which the end rear of the ash-pit 4. projects into the fire-pot for the admission of 25 5 represents a boiler supported upon the steam into the same to facilitate the eombus- 75 walls 3, having the smoke-fiue7 and the headtion of the gases before they have escaped opening 8, leading into the exit-flue 9. The from the fire-pot. front plate 10 is provided with the door 11, The operation is as follows: Fuel being leading to the smoke-flue 7 of the boiler for placed in the fire-pot 23 through the door 13,

o cleaning-out purposes, the fuel-door 13 for it is ignited in the usual manner, the damper 8c the admission of fuel, and the ash-door 15 for 50 being thrown down and back, so as to make removing the ashes from the ash-pit 4. In a direct draft to aid in starting the fire. The the ash-door 15 are arranged draft-openings air coming in through the openings in the 17 for the admission of air to the fire-box ash-door 15.rushes up through the grate-bars,

3 5 through the grate-bars 18, a sliding damper and the fuel thereon supplying the necessary 8 5 20 being arranged over the draft-openings 17 oxygen for the purpose of starting the fire, for regulating the admission of air through the smoke and unconsumed gases passing out said openings. through the opening 51 into the smoke-flue Directly under the front end of the boiler 33. WVhen the fire is sufficiently started, the

0 5 isarranged the fire-pot 23, having thedouble damper 50 is closed, forcing the gases and 90 walls and 26 on each side, and the rear products of combustion to find exit either preferably formed U-shaped, the top being through the openings between the corrugafitted up against the bottom of the boiler 5 tions of the inner lining and the inner on each side, while the rear portion 27 and walls 25 and 27 or back through the fuel and 28 is only carried up part way to the boiler, out into the smoke-flue 33 in the direction of 5 leaving an open space 51 from said fire-pot the arrows. The air, being admitted through back under the boiler, which may be closed the hollow Walls of the fire-pot, enters through by the dampers 50. The rear Wall 27 and 28 the openings 39,furnishing an additionalsupof the fire-pot is preferably set on an incline ply of air to the rising gases, which are drawn toward the back part of the furnace. The down, ignited,and are carriedoff inthe usual I00 manner in to the smoke-flue 33, thence through the boiler-Hues 7, and out of the exit-flue 9. The fuel being supplied with a sufficient amount of oxygen is always alive, and the gases which naturally arise from the fuel during combustion are carried directly through the fuel and into the smoke-flue 33, whether the current be directly toward the flue 33 or by way of the corrugated channels as they terminate above the grate-bars 18.

I claim as my invention- 1. The combination, in a furnace, of a firepot having its walls formed hollow and connected to the outer air and provided with a series of openings leading from the hollow wall into the fire-pot, a corrugated inner lining forming diving-lines, with similar corrugations on the inner wall of said fire-pot, the gratebars 18, and the smoke-flue 33, substantially as described, and for the purpose specifled.

2. The combination, in a furnace, of a firepot, an inclosing hollow wall, a series of openings from said hollow wall into said fire-pot, openings leading into said hollow wall from the outer air, a steam-pipe adapted to deliver a spray of steam in said fire-pot, and the draft-openings 17, grate-bars 18, and smokefine 33, substantially as described.

3. The combination, in a furnace, of the fire-box 23, having the walls 25 and on the sides formed U-shaped, the walls 27 and 28 at the rear formed U-shaped and of a less height than the side walls, and said walls being closed at the top, forming a hollow space between them, said hollow space being connected by suitable openings with the outer air and by a series of holes with the fire-pot 23, the damper 50, and the smoke-flue 33, substantially as described.

4. The combination, in a furnace, of the fire-pot 23, having the side walls and 26 and the rear walls 27 and 28, provided with the openings 39, a corrugated lining 30, forming with similar corrugations on the walls 25 and 27, diving-flues, the grate-bars 18, damper 50, and smoke-flue 33, substantially as described, and for the purpose specified.

5. The combination, in a furnace, of the fire-pot 23, the walls 25, 26, 27, and 28, having the series of openings 39, and the openings 37, damper 50, steam-pipe 40, diving-fines 19, grate-bars 18, ash-box 4, draft-openings 17, and smoke-flue 33, combined and constructed substantially as described, and for the purpose specified.

In testimony whereof I have hereunto set my hand this 21st day of January, 1890.

JAMES IIARKINS.

In presence of- A. 0. PAUL, A. M. GASKILL. 

